Hi Jon and the list,
I have a lot of different topics to comment and ask questions on about
future LEO ham sats. These are my views and may not be shared by
AMSAT, and the other who worked on WO-39 (JAWSAT).
At 07:12 AM 8/17/2000 -0500, you Jon wrote:
>on 8/17/00 1:00 AM, Tony Langdon at tlangdon@atctraining.com.au wrote:
>
> > Well, ideally, the linear birds are better suited to longer ragchews, as
> > they have inherently greater traffic capacity, but perhaps more FM
> > transponder space might be a good idea.
But listen to them during the week. It is usually 0, 1 or 2 QSO's going on.
On weekends you may get up to 5 QSO's. Is that a good use of a 100kHz
wide uplink on 2 meters?
>Better yet, move to the SSB birds! C'mon Tony. You seem like a good op and
>are knowledgeable about satellites. There is so much more out there than FM
>birds. I'd rather get more SSB birds up there than FM birds as they are so
>much more useful and useable by people. FM birds have too many limitations.
But are the one up there now being used that much and is there room to
put new one up on LEOs using 2 meters.
>Yet, in the ham community everyone building satellites (except P3D) is
>focusing on FM only.
Many of them including myself used FM for a digital link to the bird. We added
the FM voice to let more people use the bird when it was not over the ground
station and being commanded. It is easy to get commercial/space 2m and
70cm FSK FM equipment in our budget. Using 2 meters and a whip allows
us to command the satellite when it is spinning. Not having a high gain 70cm
antenna on the satellite also helps in satellites without attitude control.
The current bird we are working on will only
have FSK FM digital on the main 2m uplink/ 70cm downlink. We are doing this
to reduce the complexity of the main command system. It will have an
aditional 153kbps downlink on S-band.
The satellite after that will not be on the amateur band. I may be able to
add a small ham package like was done for AO-27.
I am working on an independent FM digital/voice package but with my current
resources It will not be as space worthy as it could. I just want to see
how long I can make it will work in space! I would gladly give up flying
my package and have it replaced by a L band up and S band down transponder.
I do not have the time to learn how to build and fund one of those right now.
Maybe someone in the US has one or can make one. I am not sure AMSAT-NA
has the money to fund one now. I am not sure if any of the current volunteers
are willing to take on a new project right now.
Would you donate to a call for money from AMSAT to fund a LEO transponder?
Another question I have is if a microwave transponder is useful on a LEO
satellite.
Why not another U/V Fugi like bird? There is not room for much more in the
satellite segment of 2 meters. We are all ready sharing many uplinks
between the birds.
So that leave the microwave bands. We should use those bands. Will the
hams that worked AO-10, A0-13 and hopefully soon P3D be able to deal with
the Doppler? It is really going to be fun to track the S-band Doppler on a
SSB signal. Hey just the uplink on L-band is going to change a lot. It
will force many of us to go to full computer control.
I think a better use would be to use the transponder more for digital voice
as suggested my Phil Karn.
> It's sad because we are wasting resources and money on
>a mode that is NOT appropriate for widespread use!
Is it your's or AMSAT's money and resources? It seems to me that we as hams
are getting the bent pipes for free on these new University related satellites.
I and others are trying to learn how to build satellites including
communication
links. That is enough work to keep us busy. Many (most?) of us are not RF
engineers sadly to say. Some would say we are not building amateur
satellite but
many of use working on the new birds are hams. I personally would like to
see some of the current S-Band amateur satellite band be opened up on
a shared basis for University students made satellites with a new set of
rules. And have these satellite operate under new rules but when the
university is done with their project allow it to be switched operate under
the amateur satellite rules.
Are there plans out there on how to build a space worthy
ham transponder? I have not seen any articles in the AMSAT Journal, QST, or
QEX.
When was the last time AMSAT-NA built a transponder. Even if the plans
were there for the ones they did build I am sure some of the part they used
are unavailable today.
> I bet as many hams that
>get into satellites leave due to what they hear and see on the FM birds.
>More won't help.
Well I think UO-14 took a lot of the load off of AO-27. True some of us might
be on every pass that we can of every FM bird. I am looking for 22 more grid
squares in the US. They show up a lot more on the FM birds than on the Fugi's
where you can often hear the same people calling CQ for most of the pass
on the daytime Mon-Fri passes.
I know chasing grids is not every ones cup of tea! In fact I bet a small
fraction
of the current user of the FM birds are doing it. Hey even some of those who
are going to a lot of grids to give them out are not even collecting
them. I am
happy to listen to the same people saying a quick "Hi" to each other. It is
better than hearing them call CQ on SSB for a whole satellite pass with no
one to talk to.
I also know how fun it is to make a QSO while in a boat, skiing down a hill or
on a motorcycle going down the road. This can be done but takes some
"Ham" skill to be able to pull it off. As more beginners get on the birds this
is getting much harder to do on UO-14!
Right now the passes of UO-14 when it is east of me are causing me to
reach my "frustration point". As soon as I work EM72, EM91, EM94,
FM04 and FM13 I will not even be listening to the first (far East) pass of
UO-14.
>FM is fine for packet and data as many people can share the channel. But
>for voice, there are just too many limitations.
I bet digital would also have problems if the same number of people who are
trying UO-14 now would try the same digital bird at the same time.
>And turning UO14 over to FM
>since it could no longer do packet was a WONDERFUL thing.
We we going to turn JAWSAT over a FM voice a lot sooner.
> But FM is NOT all
>there is to satellite operating.
I agree, I have over 5,600 QSO's logged on the non-FM birds. But I bet more
than 3/4 of my 427 confirmed USA grids came on the FM birds. I know many
others do not chase grid square but that is what I am doing as a user now.
When I get all of the 488 grids that I am after I will move on to something
else.
Hey I might even just go back to rag chewing with my friends on the SSB
transponders at night.
>Let's graduate to linear transponders and start putting resources and
>attention there.
> There's only a few good ones up there right now.
When was the last one put up by AMSAT-NA?
I would love to put one on our next satellite but we do not have the budget to
go out and buy one. I offered AMSAT-NA a chance to fly a package on our
satellite that was to be launched in March of 2001. The reply I got back was
they were too busy now with P3D and to do a proposal at the Oct. meeting.
My reply was Oct. was too late to start to get something on a March launch.
It looks like the launch may slip so there may still be time. If you can help
AMSAT-NA find/get the resources we would still love to fly a transponder but
we do not have time to develop it ourselves.
> Instead
>of encouraging people to stay on the FM birds and just hone their "antenna
>dancing" technique or buy a better HT, why don't we encourage them to get a
>fully developed satellite station.
I want more of you take your SSB rigs out of your "fully developed station"
and
do the arrow dance with them from new grids and counties on the Fugi's! I have
done it many times. It can be done with 2 to 3 watts and an arrow. The
trick is
to do the "dance" to peak your uplink. The downlink is much easier. Hey
even with just a 19 inch dual band vertical on my car roof and a preamp I can
hear most of the stations for most of the pass. Hey, the vertical is not a
circular polarized attenuator for parts of the pass.
------------------------------------
A few more scattered comments since the 153kbps packets stuff just
arrived on my doorstep from Germany!
I bet a lot of people are on the FM birds because they can work them from the
road! I know hams that very seldom work satellites from their home QTH!
I would like to see more people on the Fugi's but I have not seem it happen.
I know there are others that are on AO-10 chasing countries like I chase grids
but they do not seem able and or want to work the LEO's transponders.
Some day I hope to put a L/S transponder on a LEO. I wonder how many
of those "fully developed station" will be able to handle the Doppler? I want
the challenge to figure out how to work it mobile!
There is not room enough now for all the new satellites to get a FM channel
now on 2 meters let alone try to find a 10, 15 or 100 kHz wide uplink or
downlink.
73, Randy N7SFI
-------------------
How much are you on the birds Jon? I have not worked you as NA9D yet.
I have worked you as KE9NA once each on AO-27, FO-20, FO-21 and UO-14.
But then again I have worked 16 other stations that are in EN52. I now try
for the most part to only work the new stations on FM-birds. When UO-14
is loaded I try to look the new station up on QRZ before I call him
to see if he is in a grid that I need. If he is not I will let others give
them
there first satellite contact. Heavens knows I have sent out enough QSL
cards all ready (2,526).
If you want to know more about my US grid chasing project check out
http://www.xmission.com/~kohlwey/
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